Certain implantable medical devices (IMDs) have the capability to communicate data with an external communication, monitoring or control device via a telemetry link. Examples include cardiac rhythm management devices such as pacemakers and implantable cardioverters/defibrillators, and neurostimulators. Data typically transmitted between an external device and an IMD includes operating parameters, stimulus and sensing modes and physiological data.
In previous telemetry systems, the IMD and the external device communicated by generating and sensing a modulated magnetic field between the devices, with the antennas of the respective devices inductively coupled together and adapted for near-field communication. The external device included a wand having an antenna, and the wand had to be in close proximity to the IMD, typically within a few inches, in order for communications to take place.
Thus, there is a need for systems for enabling longer distance, higher data rate telemetry in implantable medical devices.